1. Field of the Invention
The present invention relates to an aluminum base alloy composed mainly of aluminum.
2. Description of the Related Art
Conventional aluminum base alloys generally have low hardness and low heat resistance. Though various attempts have been made recently, such as rapidly solidifying a molten aluminum base alloy (hereinafter referred to as “molten alloy”) to refine the structure of the alloy so as to improve the mechanical properties (such as mechanical strength) and chemical properties (such as corrosion resistance) of the aluminum base alloy, yet the properties such as strength and heat resistance of the aluminum base alloys obtained in the above manner are not sufficiently improved.
When focusing on nonequilibrium and quasi-periodic structures of the aluminum base alloys produced by a liquid rapid quenching method, there are aluminum base alloys containing amorphous phases and quasicrystalline phases. Such aluminum base alloys are more excellent in mechanical properties and chemical properties than general aluminum base alloys having crystalline phases. Particularly, the aluminum base alloy disclosed in Japanese Published Examined Patent Application No. H05-7459 and the aluminum base alloy disclosed in Japanese Published Examined Patent Application No. H05-32464 contain rare-earth elements and have an amorphous phase or a mixed composition of the amorphous phase and a fine crystalline phase. These aluminum base alloys are excellent not only in strength, heat resistance, and corrosion resistance, but also in workability of bending, etc. Therefore, these aluminum base alloys can be used as high-strength materials and high-wear resistance materials. Incidentally, the fine crystalline phase is a complex composed of a metal solid solution phase formed by an aluminum matrix, an aluminum matrix phase formed by fine crystals, and a stable or metastable intermetallic compound phase.
However, the aluminum base alloys disclosed Japanese Published Examined Patent Application No. H05-7459 and Japanese Published Examined Patent Application No. H05-3246 not only require high cost due to containing expensive high-active rare-earth elements including Y and Ce, etc., but also have low specific strength due to the high specific gravity of the rare-earth elements of Y and Ce, etc.